Airlift pump with helical flow pattern

ABSTRACT

The airlift pump with helical flow pattern includes a nozzle body having a fluid passage therethrough. A plurality of air or gas injector nozzles surrounds the central passage. The outward side of each nozzle is tangent to the fluid passage wall through the body to produce circumferential flow in the fluid passage. Each of the air injector nozzles is also inclined in the direction of flow through the body, the tangential inclination resulting in a helical flow pattern through the body. The centrifugal force generated by the circumferential and helical flow through the body results in a pressure decrease through the core of the fluid passage, thereby enhancing entrainment of fluid into the device to increase its efficiency. The fluid passage through the nozzle body is devoid of any structure, and the inlet end of the passage is smoothly radiused to further increase the efficiency of the device.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to fluid pump devices, andparticularly to an airlift pump with helical flow pattern that has aplurality of helically oriented air injection nozzles for imparting anupward helical flow pattern to the entrained fluid being drawn throughthe pump.

2. Description of the Related Art

The conventional airlift pump is a simple device, comprising a dischargeor jet of air or other gas into the lower end or portion of asubstantially vertical standpipe situated in a body of water or otherliquid. The air or gas jet entrains the liquid and lifts the liquidwithin the pipe to expel the liquid from the open top of the pipe, orfrom a discharge pipe or tube extending from the top of the pipe.Relatively small solid particulates (e.g., sand and gravel) may also belifted from the bottom of the body of water, depending upon the energyin the airstream and other factors.

Airlift pumps have no moving parts whatsoever incorporated in the pumpstructure. However, airlift pumps by their nature cannot achieve theefficiency or the lifting height of motorized mechanical pumps. Anexample of an airlift pump is found in Japanese Patent No, 2005-291,171,published on Oct. 20, 2005, which describes (according to the drawingsand English abstract) a bubble jet-type airlift pump for drawingrelatively light particulate matter from the bottom of a body of water.

Thus, an airlift pump having a helical flow pattern solving theaforementioned problems is desired.

SUMMARY OF THE INVENTION

The airlift pump with helical flow pattern includes a nozzle bodydefining a central fluid passage and having a plurality of helicallyinclined air injection nozzles surrounding the central passage. Thelaterally outward side of each of the injector nozzle passages istangent to the inner wall or surface of the central fluid passage of thenozzle body. Air (or other gas) injected into the central fluid passageproduces a circumferential flow. Each of the injector nozzle passages isalso inclined in the general direction of fluid flow through the body.The tangential and sloping orientation of the air injection passagesresults in a helical flow pattern for the air or gas injected into thenozzle body. This helical flow pattern imparts a similar flow pattern tothe fluid passing through the nozzle body. The rotating flow results ina decrease in pressure through the center of the flow due to thecentrifugal effect of the rotating fluid flow. This pressure dropenhances the entrainment of more fluid through the device, therebyincreasing its efficiency.

The tangential orientation of the air or gas injection nozzles resultsin a completely open fluid flow passage through the nozzle body, therebyfurther increasing the efficiency of the device by removing anystructure that would otherwise produce hydrodynamic resistance to flowthrough the body. The entrance to the fluid flow passage is alsosmoothly radiused in order to reduce turbulent flow at this point. Ariser or standpipe is attached to the upper or outlet end of the nozzlebody. The riser preferably has the same internal diameter as the fluidpassage of the nozzle body. The fluid passages of both the nozzle bodyand the riser preferably have uniform internal diameters to maximizesmooth flow through the apparatus. The riser or standpipe is preferablysealed to the upper end of the nozzle body to preclude leakage and flowdisruption at that point, e.g., by an O-ring or other suitable sealingmeans.

These and other features of the present invention will become readilyapparent upon further review of the following specification anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view in section of the nozzle body of an airliftpump having a helical flow pattern according to the present invention,illustrating the orientation of the air injector nozzles therein.

FIG. 2 is an elevation view in section of the airlift pump having ahelical flow pattern according to the present invention, illustratingfurther features thereof and the attachment of the riser pipe to thenozzle body.

FIG. 3 is a top plan view of the nozzle body of the airlift pump havinga helical flow pattern according to the present invention, illustratingthe tangential orientation of the air injection nozzles to the fluidpassage of the nozzle body.

FIG. 4 is a diagram of the flow pattern within the nozzle body of theairlift pump having a helical flow pattern according to the presentinvention.

FIG. 5 is a diagram of gas and particulate flow through the nozzle bodyof the airlift pump having a helical flow pattern according to thepresent invention.

Similar reference characters denote corresponding features consistentlythroughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The airlift pump having a helical flow pattern includes a plurality ofair or gas injection nozzles disposed tangentially to the wall of thecentral passage and inclined toward the upper or outlet end of thepassage to impart a helical flow to liquid entrained in the device. Thishelical flow pattern imparts additional energy to the liquid flowthrough the device in comparison to conventional flow patterns, therebyincreasing the lift height of the liquid pumped through the device.

FIG. 1 of the drawings provides a perspective view in section of theairlift pump with helical flow pattern, designated generally as 10 inthe drawings. FIG. 2 provides an additional elevation view in section ofthe airlift pump 10 that also shows the attachment of a riser pipe tothe upper end of the device. The airlift pump 10 comprises a nozzle body12 having a lower inlet end 14 and an opposite upper outlet end 16. Afluid flow passage 18 is disposed concentrically within the nozzle body12, as shown clearly in FIG. 3 of the drawings. The fluid flow passage18 extends completely through the nozzle body 12, from the inlet end 14to the outlet end 16 thereof. The lower or inlet end 14 of the fluidflow passage 18 has a smoothly rounded radius 20 to minimize turbulentflow of liquid entering the passage 18. The wall 22 of the fluid flowpassage 18 defines the internal diameter 24 of the fluid flow passage,which is constant and uniform throughout the length of the fluid flowpassage 18. It will be seen in the top plan view of FIG. 3 that thefluid flow passage 18 is completely open and devoid of any internalstructure, e.g., air inlet nozzles, etc., as found in conventionalairlift pumps.

Rather than the conventional air inlet nozzle or nozzles extending intothe flow path through the fluid flow passage 18, the airlift pump 10utilizes a plurality of tangentially disposed and inclined air injectionnozzles 26 evenly spaced circumferentially about the nozzle body 12.Four such nozzles 26 are shown in hidden lines in FIG. 3. More or fewersuch nozzles may be provided in the nozzle body, as desired. Each of thenozzles 26 has an inlet end 28 communicating with the exterior of thenozzle body 12 for the connection of an air (or other gas) supply linethereto, and an opposite outlet end 30 communicating with the fluid flowpassage 18 through the nozzle body 12. Each of the air injection nozzles26 is upwardly inclined in the direction of flow through the nozzle body12, as shown in FIGS. 1 and 2. The inlet ends 28 are disposed toward thelower or inlet end 14 of the body, and the outlet ends 30 are higher inthe body, toward the upper or outlet end 16 thereof.

It will also be seen particularly in FIG. 3 that the outlet ends 30 ofeach of the air injection nozzles 26 are laterally offset relative tothe axial centerline of the fluid flow passage 18 through the nozzlebody 12, i.e., they are tangent to the wall 22 of the fluid flowpassage. More specifically, as shown in FIG. 3, the laterally outwardside 32 of the wall of each of the air injection nozzles 26 forms atangent with the wall 22 of the fluid flow passage 18 at the outlet end30 of the nozzle. The combination of the upward inclination andtangential disposition of the air injection nozzles 26 relative to thecentral fluid flow passage 18 of the nozzle body 12 produces a helicalflow path for air (or other gas) flowing into the central fluid flowpassage 18. As the air (or other gas) entrains the liquid within thefluid flow passage 18, the liquid also develops a helical flow paththrough the fluid flow passage. The mass of the fluid within the fluidflow passage 18 is impelled to follow the contour of the wall 22 of thefluid flow passage 18 as it flows upward in the passage, thus producinga pressure drop in the center of the fluid flow passage 18. Thisreduction in pressure through the center of the fluid flow passage 18enhances the suction produced at the inlet end 14 of the nozzle body 12.As additional mass and velocity of liquid is entrained through the fluidflow passage 18 by the suction, the result is a greater lift height ofthe fluid at the nozzle body outlet end 16.

Accordingly, a riser pipe 34 (shown in FIG. 2) may be attached to theupper end 16 of the nozzle body 12 to accommodate the additional liftheight provided by the present airlift pump 10 with its helical flowpattern. The upper end 16 of the nozzle body 12 includes a riserreceptacle 36 therein concentric with the fluid flow passage 18, theriser receptacle 36 having a larger diameter 38 than the diameter 24 ofthe fluid flow passage 18 to seat the riser pipe 34 therein. The riserpipe 34 has an internal diameter 40 equal to the internal diameter 24 ofthe fluid flow passage 18 of the nozzle body 12, thereby resulting in asmooth, constant and uniform internal diameter for the nozzle body 12and riser pipe 34 assembly to minimize any impedance to fluid flowtherethrough. The riser receptacle 36 in the upper end 16 of the nozzlebody 12 further includes a circumferential annular O-ring groove 42. AnO-ring 44 is seated therein to seal the lower end 46 of the riser pipe34 within the riser receptacle 34 of the nozzle housing 16 in order toprevent the escape of fluid between the fluid flow passage 18 of thenozzle body 12 and the riser pipe 34.

FIG. 4 of the drawings provides a schematic representation of the fluidflow vectors within the fluid flow passage 18 of the nozzle body 12 ofthe airlift pump 10. In FIG. 4, four solid arrows represent the axes ofthe corresponding four injectors. Each injector axis is inclined in theradial, axial, and tangential directions, i.e., the injector axis doesnot extend radially inward into the nozzle body in a horizontal plane,but extends radially inward obliquely; similarly, the injector axis doesnot extend vertically parallel to the central axis of the nozzle body12, but at an oblique angle relative to vertical, and the injector axisis not tangential to the circumference of the nozzle body, but extendsobliquely inward and upward. The injector axis A forms an angle θ withthe vertical axis of the nozzle, and an angle φ with the radius of thenozzle. The airstreams thus injected by the nozzles have a combinationof axial, radial, and tangential components that affect motion of thefluid flow within the fluid flow passage of the nozzle body, impartingan axial flow upward through the nozzle body 12 and riser pipe 34 thatis accompanied by the radial and tangential components contributed bythe air injectors 26, result in a helical flow pattern that travelsupward in the airlift pump 10.

FIG. 5 is a schematic representation of the particulate and fluid flowthrough the fluid flow passage 18 of the nozzle body 12 of the airliftpump 10. As the air enters the pipe, the upward and circular flow withinthe fluid flow passage of the nozzle body produces an upward helicalflow pattern that results in a low pressure vortex at the lower end 14of the fluid flow passage 18, thereby entraining liquid and particulatesswept up by the liquid flow into the fluid flow passage. The swirling,helical flow pattern tends to homogenize the solid particles within theliquid phase along the entire flow passage, and further downstream(i.e., ejected from the upper end of the flow passage). The designparameters that affect the liquid and solid mass flow rates for a giveninput air mass flow rate comprise the pipe riser total length L, theavailable static height H₅, the pump static lift L_(s), the height ofthe input end of the fluid flow passage above the bottom of the fluidtank or reservoir X_(s), and the pump or fluid flow passage diameter D.The pressure of the air or gas inflow P_(in), also affects the operationof the pump.

It is to be understood that the present invention is not limited to theembodiments described above, but encompasses any and all embodimentswithin the scope of the following claims.

1. An airlift pump with helical flow pattern, comprising: a nozzle bodyhaving an inlet end and an outlet end opposite the inlet end, the nozzlebody defining a concentric fluid flow passage through the body, thefluid flow passage extending from the inlet end to the outlet end of thenozzle body and having a passage wall defining a fluid flow passagediameter; a plurality of air injection nozzles extending into the nozzlebody for the injection of air into the fluid flow passage, each of theair injection nozzles having an inlet end and an outlet end opposite theinlet end, each of the air injection nozzles having an axis wherein theoutlet end of each of the nozzles communicates with the fluid flowpassage at a non-zero angle away from tangent to the passage wall of thefluid flow passage, each of the air injection nozzles having an axisbeing inclined vertically, laterally, and radially within the nozzlebody in order to produce non-tangential helical flow of liquids throughthe fluid flow passage from the inlet end to the outlet end of thenozzle body, the outlet end of each of the nozzles being oriented towardthe outlet end of the nozzle body; a riser receptacle disposed withinthe outlet end of the nozzle body, the riser receptacle having a largerinternal diameter than the fluid flow passage; and a riser pipe having alower end disposed within the riser receptacle of the nozzle body andextending upward therefrom, the riser pipe having a smooth and uniforminternal diameter equal to the diameter of the fluid flow passage. 2.The airlift pump with helical flow pattern according to claim 1, whereineach of the nozzles has a wall having an outward side, the outward sideof the nozzle wall being tangent to the wall of the fluid flow passageat the outlet end of each of the nozzles.
 3. The airlift pump withhelical flow pattern according to claim 1, wherein the inlet end of thefluid flow passage is smoothly radiused and has a curved contour.
 4. Theairlift pump with helical flow pattern according to claim 1 wherein thediameter of the fluid flow passage is smooth and uniform from the inletend to the outlet end of the nozzle body, the fluid flow passage beingdevoid of internal structure.
 5. (canceled)
 6. The airlift pump withhelical flow pattern according to claim 1, further comprising: acircumferential O-ring groove disposed within the riser receptacle; andan O-ring disposed within the O-ring groove, the O-ring sealing theriser pipe within the riser receptacle.
 7. The airlift pump with helicalflow pattern according to claim 1 wherein the plurality of air injectionnozzles comprises four air injection nozzles, the nozzles being evenlyspaced circumferentially about the nozzle body.
 8. An airlift pump withhelical flow pattern, comprising: a nozzle body having an inlet end andan outlet end opposite the inlet end, the nozzle body defining aconcentric fluid flow passage extending through the nozzle body, thefluid flow passage extending from the inlet end to the outlet end of thenozzle body and having a passage wall defining a fluid flow passagediameter; a plurality of air injection nozzles extending into the nozzlebody for injection of air into the fluid flow passage, each of the airinjection nozzles having an inlet end and an outlet end opposite theinlet end, each of the air injection nozzles having an axis wherein theoutlet end of each of the nozzles communicates with the fluid flowpassage, each of the nozzles having a wall having an outward side, theoutward side of the nozzle wall communicating with the fluid flowpassage at a non-zero angle away from tangent to the passage wall of thefluid flow passage at the outlet end of each of the nozzles, each of theair injection nozzles having an axis being inclined vertically,laterally, and radially within the nozzle body in order to producenon-tangential helical flow of liquids through the fluid flow passagefrom the inlet end to the outlet end of the nozzle body; a riserreceptacle disposed within the outlet end of the nozzle body, the riserreceptacle having a larger internal diameter than the fluid flowpassage; and a riser pipe having a lower end disposed within the riserreceptacle of the nozzle body and extending upward therefrom, the riserpipe having a smooth and uniform internal diameter equal to the diameterof the fluid flow passage.
 9. The airlift pump with helical flow patternaccording to claim 8, wherein the outlet end of each of the airinjection nozzles is oriented toward the outlet end of the nozzle body.10. The airlift pump with helical flow pattern according to claim 8,wherein the inlet end of the fluid flow passage is smoothly radiused andhas a curved contour.
 11. The airlift pump with helical flow patternaccording to claim 8, wherein the diameter of the fluid flow passage issmooth and uniform from the inlet end to the outlet end of the nozzlebody, the fluid flow passage being devoid of internal structure. 12.(canceled)
 13. The airlift pump with helical flow pattern according toclaim 8, further comprising: a circumferential O-ring groove disposedwithin the riser receptacle; and an O-ring disposed within the O-ringgroove, the O-ring sealing the riser pipe within the riser receptacle.14. The airlift pump with helical flow pattern according to claim 8,wherein the plurality of air injection nozzles comprises four airinjection nozzles, the nozzles being evenly spaced circumferentiallyabout the nozzle body.
 15. An airlift pump with helical flow pattern,comprising: a nozzle body having an inlet end and an outlet end oppositethe inlet end, the nozzle body defining a concentric fluid flow passageextending through the nozzle body, the fluid flow passage extending fromthe inlet end to the outlet end of the nozzle body and having a passagewall defining a fluid flow passage diameter; four air injection nozzlesextending into the nozzle body, the nozzles being evenly spacedcircumferentially about the nozzle body, each of the air injectionnozzles having an inlet end and an outlet end opposite the inlet end,each of the air injection nozzles having an axis wherein the outlet endof each of the nozzles communicates with the fluid flow passage at anon-zero angle away from tangent to the passage wall of the fluid flowpassage, the inlet end of the fluid flow passage being smoothly radiusedand having a curved contour, each of the air injection nozzles having anaxis being inclined vertically, laterally, and radially within thenozzle body in order to produce non-tangential helical flow of liquidsthrough the fluid flow passage from the inlet end to the outlet end ofthe nozzle body; a riser receptacle disposed within the outlet end ofthe nozzle body, the riser receptacle having a larger internal diameterthan the fluid flow passage; and a riser pipe having a lower enddisposed within the riser receptacle of the nozzle body and extendingupward therefrom, the riser pipe having a smooth and uniform internaldiameter equal to the diameter of the fluid flow passage.
 16. Theairlift pump with helical flow pattern according to claim 15, whereinthe outlet end of each of the air injection nozzles is oriented towardthe outlet end of the nozzle body.
 17. The airlift pump with helicalflow pattern according to claim 15, wherein each of the nozzles has awall having an outward side, the outward side of the nozzle wall beingtangent to the wall of the fluid flow passage at the outlet end of eachof the nozzles.
 18. The airlift pump with helical flow pattern accordingto claim 15, wherein the diameter of the fluid flow passage is smoothand uniform from the inlet end to the outlet end of the nozzle body, thefluid flow passage being devoid of internal structure.
 19. (canceled)20. The airlift pump with helical flow pattern according to claim 15,further comprising: a circumferential O-ring groove disposed within theriser receptacle; and an O-ring disposed within the O-ring groove, theO-ring sealing the riser pipe within the riser receptacle.